Added a resetOnOutput switch to fieldAverage to allow the averaging to be only...

Added a resetOnOutput switch to fieldAverage to allow the averaging to be only of the preceding writeInterval for transient cases.

src/postProcessing/functionObjects/field/fieldAverage/fieldAverage/fieldAverage.C

@@ -308,6 +308,7 @@ Foam::fieldAverage::fieldAverage
     active_(true),
     prevTimeIndex_(-1),
     cleanRestart_(false),
+    resetOnOutput_(false),
     faItems_(),
     meanScalarFields_(),
     meanVectorFields_(),
@@ -355,6 +356,7 @@ void Foam::fieldAverage::read(const dictionary& dict)
     if (active_)
     {
         dict.readIfPresent("cleanRestart", cleanRestart_);
+        dict.readIfPresent("resetOnOutput", resetOnOutput_);
         dict.lookup("fields") >> faItems_;
 
         initialize();
@@ -387,6 +389,17 @@ void Foam::fieldAverage::write()
         calcAverages();
         writeAverages();
         writeAveragingProperties();
+
+        if (resetOnOutput_)
+        {
+            Info<< "fieldAverage: restarting averaging at time "
+                << obr_.time().timeName() << nl << endl;
+
+            initialize();
+
+            // ensure first averaging works unconditionally
+            prevTimeIndex_ = -1;
+        }
     }
 }
 

src/postProcessing/functionObjects/field/fieldAverage/fieldAverage/fieldAverage.H

@@ -41,6 +41,11 @@ Description
         // averaging info if available
         cleanRestart true;
 
+        // Whether to reset the averaged fields after they have been written.
+        // Used to average over only the preceding write interval for transient
+        // cases.
+        resetOnOutput true;
+
         // Fields to be averaged. runTime modifiable!
         fields
         (
@@ -132,6 +137,9 @@ protected:
         //- Clean restart flag
         Switch cleanRestart_;
 
+        //- resetOnOutput flag
+        Switch resetOnOutput_;
+
         //- List of field average items, describing what averages to be
         //  calculated and output
         List<fieldAverageItem> faItems_;